1. Field of the Invention
The present invention relates to a hot air blower and, particularly, to a hot air blower improved to blow air in a more focused and less spread manner and to allow a user to effectively control the extent of airflow.
2. Description of the Related Art
U.S. Pat. No. 7,065,899 discloses a gas hot air gun including a main body, an air blower, an ignition device, a nozzle and a switch set. The main body includes a barrel, a handle, a heating chamber and a mixing chamber on the inner front of the barrel. A battery set and a gas can are inside the handle. One end of the nozzle is connected to the gas can. The switch set includes a power switch and an ignition switch. Users press the power switch and have gas spray out from the nozzle into the heating chamber to generate heat. The blower sends out hot air in the heating chamber out of the main body. A metal slice to regulate the direction of air and a catalyst to avoid flames from coming out of the nozzle area are inside the heating chamber.
This patented gas hot air gun can be further improved to have better control of the gas flow rate and the heating temperatures. There may be situations in which high gas flow rate inhibits a flame from being ignited. Additionally, when gas flow rate and oxygen supply rate are increased in order to achieve a higher heating temperature, the increased supply of oxygen proportionally causes air to travel at a higher speed as the gas hot air gun includes an air passage with a fixed cross sectional area. However, air can blow out a flame when the burning speed of oxygen is slower or the density of gas is low.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.